RESUMO
Lab appliances are an integral part of orthodontics, from active treatment to retention. The quality and fit of an appliance can affect the treatment result and stability. AIMS: This study aims to determine common points of failure in orthodontic appliances, and suggest methods to reduce this rate. METHODS: A survey consisting of 23 questions was distributed to active members of the American Association of Orthodontists (AAO) via Survey Monkey. RESULTS: The most common appliance to need an adjustment was the wrap-around retainer, with the Hawley retainer as a close second. The least common appliance needing adjustment was the Essix/clear retainer. Respondents were asked which component of each appliance was most commonly responsible for an ill-fit. For Hawley and wrap-around retainers, clasps were the most common problem at 50%, whereas spring aligners had two components - clasps and labial bows, both at 38%. Ill-fitting Essix/clear retainers had gingival impingement (52%) closely followed by poor posterior seating (43%). CONCLUSIONS: Communication between the orthodontist and lab technician can be improved by establishing a quality assurance protocol for outgoing and incoming cases. The labial bow of Hawley's, wrap-arounds and spring aligners should be clearly demarcated on the casts. Impressions should be free of distortion and casts should be inspected for accuracy. Clear retainers and positioner should be trimmed to avoid gingival impingement. The type of clasp should be selected based on the anatomy of the teeth, and bands should be checked for accuracy of fit.
